Survey (again) (sorry)

I realize I made a thread similar to this recently, but my lecturer would like it a bit more formalized in the form of a survey. Link below to anyone who wouldn't mind filling out some or all of the questions, it should be fairly short and it's anonymous.

[docs.google.com]

Also, for anyone who's interested in the CNC router itself, I've recently finished the designs, haven't done the testing yet but working on getting things printed. Here's the Github/HaD links with the project info/source files for anyone interested. Not sure if posting these links is against the rules, if so I'll remove them.

[hackaday.io]
[github.com]

Thanks to anyone who took the time to fill in the survey!

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it should be fairly short and it's anonymous.

[docs.google.com]

Privacy on guugle is a joke. I'd take part on the survey, but not through this channel.

What channel would you prefer? I don't think you need to log on to answer the survey and I don't have any field asking for names/country/etc. It's just the first one that came to mind.

Pic's?

I have completed your questionnaire/survey and hope it helps.

BTW, if it had been a multiple choice I would not have bothered - most members of the RepRap community have strong ideas on every aspect of 3D printers and CNC machines multiple choice responses tend to be just noise on a chart.

Mike

Yeah, I deliberately avoided multiple choice. I figured people would want to put their own answer in for a lot of the questions and multiple choice would just lock things down unnecessarily. Also, thanks for filling it in, it's definitely a help. Right now I'm calling V1 done and I'll be building it as is to avoid any more feature creep (I've been very bad at avoiding this, especially with how many times I redesigned the z axis), but I'll definitely be taking in the results of the survey for V2.

As for pics, I assume you mean of the machine, I'm working on getting it printed at the moment, but I'll be posting pics/build logs/demos as soon as possible. Just right now my combination of old printer/old plastic/cold house means I can't print them myself and need to go through the university to do it.

EDIT: just uploaded some pictures from the OpenSCAD window and an STL render of how the printed parts and steel tubing go together. I dare not try it on my machine with all of the nuts/bolts/bearings...

Edited 2 time(s). Last edit at 05/23/2018 03:25AM by Trakyan.

Cool, thanks, the suspense was killing me, more of a pictures man than a words man...

Fair enough, it's quite a bit of hassle to look at the files if you don't have OpenSCAD already. I'm waiting till I finalize what parameters I'll be using before I post STLs of individual parts, that way anyone who's building this from provided STLs will be building the same machine as me, so it'll be easier to troubleshoot.

I bought 31.8 mm tubing for this and now I'm starting to think I should have gone with 25.4 mm to save on material/print time. I initially thought the more rigidity the better, but now that I think about it the tubing wont be the weakest link.

I have some round 35mm tubing(all around one of the printers) and it was a pain to print for, drilling it would make things a little easier but i wanted to keep the tubes as they came, I've only done one or 2 parts for it, they end up quite big, it may never see another plastic part again, unless I can mount a spindle on it sometime, but a spindle mount could be huge so i'd go for metal.
square frame/tube is better to work with, some bearing for runners same as on the round tube.

Edited 1 time(s). Last edit at 05/24/2018 06:22PM by MechaBits.

I'm not too sure what you were saying in the first part of your post. I asked in my other thread if anyone had any thought on round vs square tubes and the only person that chipped in said go for round since there's less opportunity for misalignment (rotate the tube along the axis and it's still the same). That and round tubes can be clamped more neatly(?), whereas a socket style clamp on a square tube would tend to put pressure on specific parts of the tube and lift pressure from others. Lastly, square tube was the more expensive option here, so that made my mind up considering there weren't any big pros/con out there.

You shouldn't need to drill any holes in anything for this design, just need to cut the tubes down to size. I saw the MPCNC needs a few holes drilled and realized that I was too lazy to do that, and don't have a good enough drill/drillbit to drill through steel tubing (plus drilling a hole in a pipe is a pain, let alone getting them to line up, especially with a handheld drill). I'm guessing I'm not the only one in this situation of laziness/lack of tools so I made sure to avoid all drilling for my design.

I hadnt seen your call on round vs square, I get the fact that whichever way round the tube is its ok, but things could rotate around one tube. My tubes are put together with clamps, and if I have to print something its a split part so I can clamp it on, even the metal clamps I have can twist if not tight enough, too much pressure I could bend the tube with these clamps, but with printed parts I also need to build out flat faces to build onto...I think I did say a while back about my hifi stand for £10 made with sqr tube, & pretty nicely aligned already, but you wanted to start with a bare component anyone could pick up. No worries its your call, it could have differentiated it more from MPCNC & maybe improved it.

I'm not to sure what the mounting issue would be, MPCNC and most scaffolding uses round tube with clamps just fine. Square tube also means you'd need to use 4 bearings instead of 3 around the rail, aside from the added hardware it also has the chance of riding off-center, whereas 3 bearings on a round tube have a sort of self centering effect. I also didn't want to use 2 pieces clamps,The MPCNC uses those and I just feel like it's more hassle to print/assemble.

I realize it looks like the MPCNC, and that's a fact I'll have to deal with. I just chose round because it made things easier and cheaper (my main goals). I don't think I could get away from the MPCNC as long as I'm using a crossed axis type design.

If you're keen on a square tube design I could put one together for you after a week or two, right now it's my end of semester so exams and assignments have me busy. I probably wont be able to personally verify that the square design will work for a while (cant't even do it for the round yet), so it's a print at your own risk. I might build/test a square one in the future, but right now it looks like a fairly distant build.

No you dont need to make a square one just for me, I already played with the hifi stand & cube,
Key clamps & scaffold is metal so they can get away with it, my 35mm pole clamps are 2 piece metal,
I think splitting the part is better for 3D printing, stronger, better oriented, easy to remove, tighter grip,
but saying that i was never happy with the grip and wished for a hole to stop rotation,
obviously you must have made the parts dependent on other tube's to stop rotation, I couldnt really do that as I had the metal clamps at the ends/corners, and they had no mounting holes otherwise it would have been much easier.
Also you corner tubes probably fix to base, and may be arent too high.

Edited 1 time(s). Last edit at 05/26/2018 10:49AM by MechaBits.

Rotation shouldn't matter in the machine I designed, you could in theory have all the tubes spinning along their axis while it works, it just means the tube would be sliding sideways the bearings as it spins. There shouldn't be any force trying to rotate the tubes during operation.

As for print orientation for strength, I think it's optimal the way it is. The layers make a sort of diagonal cut across the cylindrical clamp. That way they won't split from the clamping screws/bolts like if it was just a vertical cylinder, and they won't delaminate when tightened around the tube if it were a cylider printed flat.

So any progress about these cheap CNC, 3D printer kit designs, surveys etc ???

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"A comical prototype doesn't mean a dumb idea is possible" (Thunderf00t)

thought i mentioned it somewhere, the design is complete and published. Github under bevelcnc, ive got some things to commit tomorrow (mostly stuff to reduce print time and material use).
i havent printed anything yet for three reasons: ive had exams and two jobs to deal with up until last week (still have the jobs luckily), i decided to try and implement a remote string driven z axis over the threaded rod the design currently uses (for fun, just trying something new that i havent seen done elsewhere), and it being the height of winter here temperatures have started dipping sub zero so my abs is most disagreeable.

im also working on trimming down the material required since im not exactly rolling in filament or the money to buy more when i stuff up\run out. I'm trying to do it once do it right, but if youd like to be the first to build it feel free.

I get that bootstrapping a cnc with less than ideal parts seems like a horrible travesty to you, but im just working within my constraints and sharing my work with anyone who feels like duplicating it. I'm not holding you at gunpoint and demanding you buy/print/worship the thing.

heres the github link if youre curious.
[github.com]

In short, the answer is "no".

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"A comical prototype doesn't mean a dumb idea is possible" (Thunderf00t)

Am I behind on my quota? This is a hobby project, I have other things I need to prioritize, bills to pay etc. If you want to see the machine completed asap feel free to print the parts yourself, I'll help you where I can. I don't see why you're acting so snarky.

Men aren't particularly agreeable...so dont worry about it, but after doing all the work to make it parametric, there really needs to be one made before you'll get enough interest in it, did you design it around a particular router/spindle? ie a small one 400w or smaller?

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MechaBits
Men aren't particularly agreeable...so dont worry about it, but after doing all the work to make it parametric, there really needs to be one made before you'll get enough interest in it, did you design it around a particular router/spindle? ie a small one 400w or smaller?

I get that, and I'm not expecting a huge amount of interest in what is basically just an idea right now. The 'release' was rushed because of how it was tied to my uni course. I just don't see why the response has to be so snarky. I'm not trying to sell this to anyone of force anyone to build it, if you're not interested just ignore it. I don't bash every rig I'm not going to build. While I give TDD a lot of flack for his high end (not sure what the right word is?) opinions because I'm a 'good enough' kind of guy and his preferences tend to favor 'nothing but the best', I fully respect that he has a great setup and all the work he's put into it.

As for your question, the effector is 'blank' with just 4 mounting holes for a toolholder. Right now I plan to use the cheap rotary tool I already have, but when I decide to upgrade or swap toolheads, I don't want to have to deal with all the installation/extra printing time that would be involved with replacing a z carriage with a specific and integrated tool mount. I'm a big fan of reducing part count and its usually one of my top goals but I also like modularity and it tends to get prioritized when I think I'd want to change specific aspects of part/assembly after the machine is built, like the tool in this case. I haven't yet updated the github because the wifi on my laptop has been gradually getting worse and worse until it kicked the bucket recently, not sure what the issue is exactly, just that beyond a few meters from the router it loses all signal and even when its right beside it the signal strength is no more than half. On the bright side the wifi works marginally better with a Linux live boot for some reason so I'm working on installing it now.

there's also a lot of shopfloor humour which basically seems to revolve around taking the piss (hopefully with some good intention thrown in), a hard crowd to please, maybe its more beneficial to point out the flaws than to say "ship it" or "send it" I had a GF who was so agreeable it really wasn't good...also wasnt good after I encouraged her to be less agreeable...cant win

Edited 1 time(s). Last edit at 07/03/2018 11:44AM by MechaBits.

Pointing out flaws is fine, but a number of these are compromises I made deliberately so that I could afford to build the machine (eventually). Besides, most of the comments aren't pointing out the flaws they're just plain snarky.

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MKSA
So any progress about these cheap CNC, 3D printer kit designs, surveys etc ???

I'd expect this sort of attitude if I was telling everyone to throw out their cast iron knee mills, but I like to think I made it clear this is just an option that functions for those that cant shell out 1k+ on a commercial machine that probably works better. I wanted a cnc mill, I knew my budget was rock bottom and this is what I came up with. Stick to your fancier kit if you've got it, I would too.

I had two main goals, make it big, make it cheap, and let it move a toolhead in 3 axis. Everything else was relegated to 'the best I can do without going against those design goals. I'm probably going to end up making a CNC that's made with smaller work envelopes in mind later, since I only really need a big-ish area for one project. It'll probably use bushings instead of the radial bearing rollers I'm using at the moment.

Hi Trakyan,

I fill it your survey in.

As you may have readen in my first post I started with a CNC router. I also did it in plywood with drawer runner. It is motorized with big Nema 17 with belts.

Take care to noise, vibrations and heat in your conception.

Best Regards

Alain